Radiology, Vol 172, 771-781, Copyright © 1989 by Radiological Society of North America
Improved MR images of the brain with use of a gated, flow-compensated, variable-bandwidth pulse sequence
D Enzmann and GT Augustyn
Department of Diagnostic Radiology and Nuclear Medicine, Stanford University School of Medicine, CA 94305-5105.
Peripheral gating and first-order flow compensation were compared for their
ability to improve the quality of second-echo (echo time = 80 msec) brain
images obtained with a T2-weighted spin-echo sequence. The
contrast-to-noise ratios (C/Ns) for interfaces between brain and
cerebrospinal fluid, gray and white matter, and lesion and white matter
were measured; the C/N was highest for the combination of gating and flow
compensation. This combination of motion compensation also reduced motion
artifacts more than did either technique alone. Further improvement in C/N
was sought by using a variable-bandwidth pulse sequence, which was compared
to a conventional spin-echo sequence. The variable-bandwidth technique
increased the C/N of the second-echo image by 27%. The combined use of
gating, flow compensation, and the variable- bandwidth option produced
high-resolution brain images with a single excitation and retained
flexibility in number of sections, number of echoes, and echo times.
